BOURNE — We seethe by the millions, motorists stranded in the traffic that can bog down the bridges that connect Cape Cod to the mainland. In a summertime ritual of vacation-time futility, we stomp on our brakes, tear out our hair, and glare at the red “heavy traffic” symbols on our smartphone apps.

But it’s worth considering this: There’s a fair chance that the cars we are stranded in, the shoes that pump those brakes, and those smartphones with their baleful warnings all came to us through that canal.

And this: Since opening 100 years ago this month, an event being commemorated in a weeklong celebration that started Friday, the canal has without a doubt saved hundreds of ships, innumerable tons of cargo, and countless sailors’ lives. Building it, an idea that dates back nearly 400 years, was a feat of engineering and entrepreneurial tenacity that is worth celebrating as you choke on the exhaust of the car in front of you, which was probably produced by oil products shipped to Boston via the canal.

“Cars, ethanol, cement, gypsum, household goods, clothes, oil, scrap iron, books, toys, computers,” said Elisa Carey, a park ranger for the US Army Corps of Engineers, which maintains the canal, rattling off things the vessels carry through it to Boston. “The list goes on and on.”

Simple maritime logic and topographic reality dictated the need for a canal. Before it was opened in 1914, ships bound for Boston from the south had to negotiate the tricky tides, shifting sands, stormy winds, and unpredictable fog off the Cape and Islands. Especially treacherous was negotiating the waters off the Outer Cape, known as a “Graveyard of the Atlantic.”

“It was taking your life in your hands,” said Rear Admiral Richard Gurnon, president of the Massachusetts Maritime Academy, which sits at the Buzzards Bay entrance to the Cape Cod Canal.

On a map in his office he displayed the stretch of shoreline where many a ship met its watery end. “Mariners would typically sail as close to land as they dared, and terrible nor’easters would just drive them into the shore.”

The idea for a canal came up as early as 1623, when Myles Standish of Plymouth Colony saw its potential to improve trade with both Dutch merchants sailing up from New Amsterdam and local Native American tribes on the southern shore of the Cape.

For the next 250 years, proposals for a canal were considered and dropped as unfeasible. Several times after 1880, as the shipwrecks piled up, charters were granted to construct a canal. But laborers with shovels and wheelbarrows were not up to the task; nor were the earliest dredges. Their bane: large granite boulders deposited by glaciers.

“People think the Cape is all sand; that’s not true,” Gurnon said. “Dig a hole, you’ll find a rock.”

It was August Belmont Jr., the financier who had helped build the New York Subway, who solved the riddle of the boulders. He blew them up. It was tricky work: He had to wait for low tide and send divers down who would drill holes in the rocks, put in explosives, and detonate them.

“It was time consuming; it was expensive; it was deadly,” Gurnon said.

The job, begun in June 1909, was also made possible by the invention of steam-powered dredges that earlier builders lacked.

Belmont created the canal by connecting the Scusset and Manomet Rivers, cutting through the highland that separated them. Finally, in July 1914, the Cape Cod Canal opened, 100 feet wide, 25 feet deep, more than enough for typical ships of that era.

“It saved 150 miles, two days of travel,” Gurnon said.

Belmont had hoped to make a profit by charging a toll, hundreds of dollars for the largest ships, Carey said. But he built nothing to slow erosion, and his dredging equipment was not up to the task of keeping his channel deep enough.

Eventually, ships stopped using it, and his canal failed. The federal government bought the canal from his company for $11.5 million
and took possession in 1928.

Financed by New Deal funds, the Army Corps of Engineers between 1935 and 1940 widened the channel to its current 480 feet, which the corps website calls the widest sea-level canal in the world; dredged it to a depth of 32 feet, which even today accommodates all but the largest cargo ships and cruise liners; and lengthened it to 17.4 miles, 8.1 miles cut through land, the rest in the approaches from Cape Cod Bay and Buzzards Bay. Riprap barriers of stone prevent erosion, modern dredging equipment maintains uniform depth and width.

The bridges we like to curse appeared. And, eventually, so did the hiking trails, fishing areas, bike paths, beaches, and parks that, along with the canal itself, attract some 3 million visitors each year, according to Marie Oliva, head of the Cape Cod Canal Region Chamber of Commerce.

Oliva and other business leaders hope that more people are drawn in by the celebrations, which started Friday with tours of tall ships docked at the Maritime Academy, and will feature a gala “Canaliversary” celebration on the official centennial commemoration on Tuesday.

They rankle at the notion that many visitors see the canal as a thing you cross to reach the Cape (the peninsula actually starts on the mainland side of the canal), and they believe the waterway to be an attraction to rival the National Seashore.

“The perception is you won’t be on the Cape until you go ever the bridge,” Oliva said. “We got this huge amenity here, and we need to let people know about it.”

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.

Thanks & Welcome to Globe.com

You now have unlimited access for the next two weeks.

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.